THE BUTEYKO METHOD

In 1957, a Ukrainian doctor named Konstantin Buteyko observed that people battling anxiety and sleep disorders often breathed through the mouths, using the upper chest more predominantly, and with a respiratory rate and volume greater than normal.

His method involves slow breathing and breath holds following an exhalation, the objective being to take less air into the lungs. This has been found to ease feelings of anxiety and stress. His method borrows from Eastern breathing techniques and is similar to some breathing exercises common in yoga.